Adjusting Unloader-Advisability?

[GaryK]

We have a BE belt drive machine with a Honda 13hp engine and Cat pump--4gpm/3600 psi. Recently, water began leaking from the bottom of the unloader valve, an OEM valve with one of the common red knobs on top. Well, we traced the problem (we thought) to a simple O-ring, replaced it and it soon began leaking again. This time we noticed the stainless steel balls were deformed and there was no way this looked to be repairable. So we replaced the unloader.

We were told by our supplier that we should go easy on adjusting the unloader valve, that those are not designed to be turned often. Because of the difficulty of turning it, I have often wondered about that issue. I wonder if there are any bits o' wisdom here about that issue.

Thanks in advance.
Gary in Portland

[MMI Enterprises]

Best advice.. don't turn them after initial adjustment. Adjust pressure down by selecting tip orifice sizes that are larger than what your machine calls for which is about a 4.5 or 4. More like a 4.25 but don't think they make such.. Have a look at the provided chart..